I was watching the Jack Daniels BBQ championships, and I noticed that everyone would keep their meat moist by spraying something on it with a spray bottle. Any ideas on what the liquid might be? I was thinking cider vinegar, but Im not sure.

I use a spray bottle everytime I smoke with different types of liquids based on the type of meat that I am smoking. Most of the time (for pork at least) it is apple cider. I only use 100% pure apple cider not some apple juice from concentrate. It is a great flavor especially when I use apple wood in the fire. For other meats I will use some sort of mop sauce that is 100% liquid - a spray bottle will create a huge mess if you try to use a liquid with some spices in it since they will get cloged.

I haven't found a spray bottle that doesn't clog up. Even pure cider has little bits of apple. Any recommendations for a source?

Filter it through some cheesecloth. Me, I use apple juice (100% pure) or water (not from concentrate). Don't be afraid to use apple juice because dkirn says not to, or for that matter, your water pan if you have a water smoker

A coffee filter will also work. You can put the spices in any solution you prefer, boil it to get some flavor out of the spices, and then strain it. I also like to use a gardening spray gadget (the one that looks a like a jug and has a pump in the lid). These sprayers have long hoses and tips and they can reach deep into the smoker. They also have a built in filter to prevent clogging.

I have always used a spray bottle. They work great. Easier to clean than a mop. I normally use a combination of apple cider and apple cider vinegar. But, for a special ham, try apple cider, apple cider vinegar, and Captain Morgans Spiced Rum, equal parts. Makes for a great flavored ham! rb